Add a rel="canonical" link to the <head> section of the non-canonical version of each HTML page.

So only for pages who are URLS leading to the same content, and only the ones you consider "copies" (so the original/main/indexable page does not need a canonical meta). You also don't need the whole URL with schema and domain: they can be relative, so<link rel="canonical" href="/signup-stepone" />would be fine.